Which of these flags is not a tricolour?

The national flag of Latvia was used by independent Latvia from 1918 until the country was occupied by the Soviet Union in 1940. Its use was suppressed during Soviet rule. On 27 February 1990, shortly before the country regained its independence, the Latvian government re-adopted the traditional red-white-red flag.

Though officially adopted in 1923, the Latvian flag was in use as early as the 13th century. The red colour is sometimes described as symbolizing the readiness of the Latvians to give the blood from their hearts for freedom and their willingness to defend their liberty. An alternative interpretation, according to one legend, is that a Latvian leader was wounded in battle, and the edges of the white sheet in which he was wrapped were stained by his blood. The white stripe may stand for the sheet that wrapped him. This story is similar to the legend of the origins of the flag of Austria.